Kernel problem

Hi, I am very new to Linux, and I have just downloaded RedHat 9.0 and updated it. When I updated it I also updated the kernel from an old version to a newer version. The problem is that the new version doesn't work properly. If I boot with the newer kernel version it works fine at first, but when I want to shut my computer off it hangs when trying to close the eth0.This does not happend when I boot with the old version of the kernel.